Stochastic finite-fault modeling of ground motions from the June 27, 1998 Adana-Ceyhan earthquake

In this study, acceleration time histories of the June 27, 1998 Adana-Ceyhan (Turkey) earthquake, are simulated using a stochastic modeling technique for finite faults proposed by Beresnev and Atkinson (1997). The fault length, width and the depth to the top of the fault for the earthquake are assumed 30 km, 21 km and 15 km, respectively, based on the aftershock distribution. Simulations are made for two common site classes: soil and rock. Their response characteristics are obtained from the site-specific amplification functions estimated for the weak motion seismograms at stations located in the region using spectral ratio methods. The results show that the overall agreement between simulated and observed waveforms and spectra is quite satisfying. However, significant discrepancies exist at certain stations, implying that site amplification functions play an important role in the simulation process. The effects of nonlinearity and basin edge generated surface waves do not clearly dominate on the results. The peak horizontal acceleration contours estimated using the calibrated model are consistent with the observed intensity values and the other evidences of strong ground motions.